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United States Patent |
6,133,298
|
Muller
,   et al.
|
October 17, 2000
|
Fungicidal mixtures
Abstract
Fungicidal mixtures, comprising a) a carbamate of the formula I
##STR1##
where T is CH or N, n is 0, 1 or 2 and R is halogen, C.sub.1 --C.sub.4
--alkyl or C.sub.1 --C.sub.4 --haloalkyl, it being possible for the
radicals R to be different when n is 2, and/or
b) an oxime ether of the formula II
##STR2##
where X is oxygen or amino (NH);
Y is CH or N;
Z is oxygen, sulfur, amino (NH) or C.sub.1 --C.sub.4 --alkylamino
(N--C.sub.1 --C.sub.4 --alkyl);
R' is C.sub.1 --C.sub.6 --alkyl, C.sub.1 --C.sub.6 --haloalkyl, C.sub.3
--C.sub.6 --alkenyl, C.sub.2 --C.sub.6 --haloalkenyl, C.sub.3 --C.sub.6
--alkynyl, C.sub.3 --C.sub.6 --haloalkynyl, (C.sub.3 --C.sub.6
--cycloalkyl)methyl, or is benzyl which may be partially or fully
halogenated and/or carry one to three of the following radicals: cyano,
C.sub.1 --C.sub.4 --alkyl, C.sub.1 --C.sub.4 --haloalkyl, C.sub.1
--C.sub.4 --alkoxy, C.sub.1 --C.sub.4 --haloalkoxy and C.sub.1 --C.sub.4
--alkylthio;
and
c) a dinitroaniline of the formula III
##STR3##
in a synergistically active amount.
Inventors:
|
Muller; Bernd (Frankenthal, DE);
Sauter; Hubert (Mannheim, DE);
Ammermann; Eberhard (Heppenheim, DE);
Lorenz; Gisela (Hambach, DE);
Strathmann; Siegfried (Limburgerhof, DE);
Schelberger; Klaus (Gonnheim, DE);
Scherer; Maria (Landau, DE);
Mappes; Dietrich (Westheim, DE);
Leyendecker; Joachim (Landenburg, DE);
Bayer; Herbert (Mannheim, DE);
Muller; Ruth (Friedelsheim, DE)
|
Assignee:
|
BASF Aktiengesellschaft (Ludwigshafen, DE)
|
Appl. No.:
|
171618 |
Filed:
|
October 22, 1998 |
PCT Filed:
|
April 23, 1997
|
PCT NO:
|
PCT/EP97/02043
|
371 Date:
|
October 22, 1998
|
102(e) Date:
|
October 22, 1998
|
PCT PUB.NO.:
|
WO97/40687 |
PCT PUB. Date:
|
November 6, 1997 |
Foreign Application Priority Data
| Apr 26, 1996[DE] | 196 16 691 |
| Apr 29, 1996[DE] | 196 17 071 |
| Sep 02, 1996[DE] | 196 35 516 |
Current U.S. Class: |
514/352; 514/383; 514/407; 514/508; 514/538; 514/618; 514/619 |
Intern'l Class: |
A01N 043/40; A01N 037/18; A01N 037/52; A01N 043/56; A01N 043/64 |
Field of Search: |
514/407,383,352,508,538,618,619
|
References Cited
Foreign Patent Documents |
0741 970 | Nov., 1996 | EP.
| |
9521153 | Aug., 1995 | WO.
| |
9601256 | Jan., 1996 | WO.
| |
9601258 | Jan., 1996 | WO.
| |
Other References
Tomlin; The Pesticide Manual Incorporating The Agrochemicals Handbook,
10.sup.th Ed. (1995) pp. 474-475.
Weeds, vol. 15, Jan. 1967, No. 1, 20-22.
|
Primary Examiner: Robinson; Allen J.
Attorney, Agent or Firm: Keil & Weinkauf
Parent Case Text
This application is a 371 of PCT/EP97/02043, filed Apr. 23, 1997.
Claims
We claim:
1. A fungicidal composition comprising synergistically effective amounts of
a) a carbamate I
##STR9##
where T is CH or N, n is 0, 1 or 2 and R is halogen, C.sub.1 --C.sub.4
-alkyl or C.sub.1 --C.sub.4 -haloalkyl, it being possible for the radicals
R to be different if n is 2,
and
c) a dinitroaniline III
##STR10##
2. The fungicidal composition defined in claim 1 wherein the weight ratio
of the dinitroaniline III to the carbamate I is from 200:1 to 0.1:1.
3. The fungicidal composition defined in claim 1, further comprising an
oxime ether II wherein the substituents have the following meaning:
X is oxygen or amino (NH);
Y is CH or N;
Z is oxygen, sulfur, amino (NH) or C.sub.1 --C.sub.4 -alkylamino
(N--C.sub.1 --C.sub.4 -alkyl);
R' is C.sub.1 --C.sub.6 -alkyl, C.sub.1 --C.sub.6 -haloalkyl, C.sub.3
--C.sub.6 -alkenyl, C.sub.2 --C.sub.6 -haloalkenyl, C.sub.3 --C.sub.6
-alkynyl, C.sub.3 --C.sub.6 -haloalkynyl, C.sub.3 --C.sub.6
-cycloalkylmethyl, or benzyl which may be partially or fully halogenated
and/or may carry one to three of the following radicals: cyano, C.sub.1
--C.sub.4 -alkyl, C.sub.1 --C.sub.4 -haloalkyl, C.sub.1 --C.sub.4 -alkoxy,
C.sub.1 --C.sub.4 -haloalkoxy and C.sub.1 --C.sub.4 -alkylthio.
4. The fungicidal composition defined in claim 3 wherein the weight ratio
of the dinitroaniline III to the carbamate I is from 200:1 to 0.1:1.
5. The fungicidal composition defined in claim wherein the weight ratio of
the dinitroaniline III to the oxime ether II is from 200:1 to 0.1:1.
6. A method of controlling harmful fungi which comprises treating the
harmful fungi, their environment, or plants, seeds, soils, areas,
materials or spaces to be kept free from said fungi with synergistically
effective amounts of a carbamate I and a dinitroaniline III as set forth
in claim 1.
7. The method defined in claim 6, wherein the carbamate I and the
dinitroaniline III are applied simultaneously together or separately or in
succession.
8. The method defined in claim 6, wherein the carbamate I is applied in an
amount of from 0.005 to 0.5 kg/ha.
9. The method defined in claim 6, wherein the dinitroaniline III is applied
in an amount of from 0.1 to 10 kg/ha.
10. The method defined in claim 6, further comprising treating the harmful
fungi, their environment, or the plants, seeds, soils, areas, materials or
spaces to be kept free from said fungi with a synergistically effective
amount of an oxime ether II
##STR11##
wherein the substituents have the following meaning: X is oxygen or amino
(NH);
Y is CH or N;
Z is oxygen, sulfur, amino (NH) or C.sub.1 --C.sub.4 -alkylamino
(N--C.sub.1 --C.sub.4 -alkyl);
R' is C.sub.1 --C.sub.6 -alkyl, C.sub.1 --C.sub.6 -haloalkyl, C.sub.3
--C.sub.6 -alkenyl, C.sub.2 --C.sub.6 -haloalkenyl, C.sub.3 --C.sub.6
-alkynyl, C.sub.3 --C.sub.6 -haloalkynyl, C.sub.3 --C.sub.6
-cycloalkylmethyl, or benzyl which may be partially or fully halogenated
and/or may carry one to three of the following radicals: cyano, C.sub.1
--C.sub.4 -alkyl, C.sub.1 --C.sub.4 -haloalkyl, C.sub.1 --C.sub.4 -alkoxy,
C.sub.l --C.sub.4 -haloalkoxy and C.sub.1 --C.sub.4 -alkylthio.
11. The method defined in claim 10, wherein the carbamate I and the
dinitroaniline III are applied simultaneously together or separately or in
succession.
12. The method defined in claim 10, wherein the oxime ether II and the
dinitroaniline III are applied simultaneously together or separately or in
succession.
13. The method defined in claim 10, wherein the carbamate I is applied in
an amount of from 0.005 to 0.5 kg/ha.
14. The method defined in claim 10, wherein the oxime ether II is applied
in an amount of from 0.005 to 0.5 kg/ha.
15. The method defined in claim 10, wherein the dinitroaniline III is
applied in an amount of from 0.1 to 10 kg/ha.
Description
The present invention relates to a fungicidal mixture which comprises
a) a carbamate of the formula I
##STR4##
where T is CH or N, n is 0, 1 or 2 and R is halogen, C.sub.1 --C.sub.4
-alkyl or C.sub.1 --C.sub.4 -haloalkyl, it being possible for the radicals
R to be different when n is 2, and/or
b) an oxime ether of the formula II
##STR5##
where
X is oxygen or amino (NH);
Y is CH or N;
Z is oxygen, sulfur, amino (NH) or C.sub.1 --C.sub.4 -alkylamino
(N--C.sub.1 --C.sub.4 -alkyl);
R' is C.sub.1 --C.sub.6 -alkyl, C.sub.1 --C.sub.6 -haloalkyl, C.sub.3
--C.sub.6 -alkenyl, C.sub.2 --C.sub.6 -haloalkenyl, C.sub.3 --C.sub.6
-alkynyl, C.sub.3 --C.sub.6 -haloalkynyl, (C.sub.3 --C.sub.6
-cycloalkyl)methyl, or is benzyl which may be partially or fully
halogenated and/or carry one to three of the following radicals: cyano,
C.sub.1 --C.sub.4 -alkyl, C.sub.1 --C.sub.4 -haloalkyl, C.sub.1 --C.sub.4
-alkoxy, C.sub.1 --C.sub.4 -haloalkoxy and C.sub.1 --C.sub.4 -alkylthio;
and
c) a dinitroaniline of the formula III
##STR6##
in a synergistically active amount.
Moreover, the invention relates to methods of controlling harmful fungi
with mixtures of the compounds I and/or II and III and to the use of the
compounds I and/or II and the compound III for the preparation of such
mixtures.
The compounds of the formula I, their preparation and their action against
harmful fungi have been disclosed in the literature (WO-A 96/01,256 and
WO-A 96/01,258).
Compounds of the formula II, their preparation and their action against
harmful fungi have been described in WO-A 95/21,153, WO-A 95/21,154 and
DE-A 195 28651.0.
The compound III (CAS RN: 79622-59-6, common name: fluazinam;), its
preparation and its action against harmful fungi have also been disclosed.
It was an object of the present inventions to provide mixtures which have
an improved activity against harmful fungi combined with a reduced total
amount of active ingredients applied (synergistic mixtures) with a view to
reducing the rates of application and to improving the spectrum of action
of the known compounds.
Accordingly, we have found that this object is achieved by the mixture
defined at the outset. Moreover, we have found that better control of the
harmful fungi is possible by applying the compounds I and/or II and the
compound III simultaneously together or separately or by applying the
compounds I and/or II and the compound III in succession than when the
individual compounds are used.
The present invention covers binary mixtures of the mixtures I and III or
II and III and also ternary mixtures of I, II and III.
In particular, the formula I represents carbamates in which the combination
of the substituents corresponds to one line of the table which follows:
TABLE 1
______________________________________
No. T R.sub.n
______________________________________
I.1 N 2-F
I.2 N 3-F
I.3 N 4-F
I.4 N 2-Cl
I.5 N 3-Cl
I.6 N 4-Cl
I.7 N 2-Br
I.8 N 3-Br
I.9 N 4-Br
I.10 N 2-CH.sub.3
I.11 N 3-CH.sub.3
I.12 N 4-CH.sub.3
I.13 N 2-CH.sub.2 CH.sub.3
I.14 N 3-CH.sub.2 CH.sub.3
I.15 N 4-CH.sub.2 CH.sub.3
I.16 N 2-CH(CH.sub.3).sub.2
I.17 N 3-CH(CH.sub.3).sub.2
I.18 N 4-CH(CH.sub.3).sub.2
I.19 N 2-CF.sub.3
I.20 N 3-CF.sub.3
I.21 N 4-CF.sub.3
I.22 N 2,4-F.sub.2
I.23 N 2,4-Cl.sub.2
I.24 N 3,4-Cl.sub.2
I.25 N 2-Cl, 4-CH.sub.3
I.26 N 3-Cl, 4-CH.sub.3
I.27 CH 2-F
I.28 CH 3-F
I.29 CH 4-F
I.30 CH 2-Cl
I.31 CH 3-Cl
I.32 CH 4-Cl
I.33 CH 2-Br
I.34 CH 3-Br
I.35 CH 4-Br
I.36 CH 2-CH.sub.3
I.37 CH 3-CH.sub.3
I.38 CH 4-CH.sub.3
I.39 CH 2-CH.sub.2 CH.sub.3
I.40 CH 3-CH.sub.2 CH.sub.3
I.41 CH 4-CH.sub.2 CH.sub.3
I.42 CH 2-CH(CH.sub.3).sub.2
I.43 CH 3-CH(CH.sub.3).sub.2
I.44 CH 4-CH(CH.sub.3).sub.2
I.45 CH 2-CF.sub.3
I.46 CH 3-CF.sub.3
I.47 CH 4-CF.sub.3
I.48 CH 2,4-F.sub.2
I.49 CH 2,4-Cl.sub.2
I.50 CH 3,4-Cl.sub.2
I.51 CH 2-Cl, 4-CH.sub.3
I.52 CH 3-Cl, 4-CH.sub.3
______________________________________
The compounds I.12, I.23, I.32 and 1.38 are especially preferred.
The general formula II represents in particular oxime ethers where X is
oxygen and Y is CH or X is amino and Y is N.
In addition, preference is given to compounds II where Z is oxygen.
Likewise, preference is given to compounds II where R' is alkyl or benzyl.
With a view to their use in the synergistic mixtures according to the
invention, compounds II which are particularly preferred are those listed
in the tables below:
TABLE 2
Compounds of the formula IIA where for each compound ZR' corresponds to one
row in Table A
##STR7##
TABLE 3
Compounds of the formula IIB where for each compound ZR' corresponds to one
row in Table A
##STR8##
TABLE A
______________________________________
No. ZR'
______________________________________
II.1 O--CH.sub.2 CH.sub.2 CH.sub.3
II.2 O--CH(CH.sub.3).sub.2
II.3 O--CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3
II.4 O--CH(CH.sub.3)CH.sub.2 CH.sub.3
II.5 O--CH.sub.2 CH(CH.sub.3).sub.2
II.6 O--C(CH.sub.3).sub.3
II.7 S--C(CH.sub.3).sub.3
II.8 O--CH(CH.sub.3)CH.sub.2 CH.sub.2 CH.sub.3
II.9 O--CH.sub.2 C(CH.sub.3).sub.3
II.10 O--CH.sub.2 C(Cl).dbd.CCl.sub.2
II.11 O--CH.sub.2 CH.dbd.CH--Cl (trans)
II.12 O--CH.sub.2 C(CH.sub.3).dbd.CH.sub.2
II.13 O--CH.sub.2 --(cyclopropyl)
II.14 O--CH.sub.2 --C.sub.6 H.sub.5
II.15 O--CH.sub.2 --[4-F--C.sub.6 H.sub.4 ]
II.16 O--CH.sub.2 CH.sub.3
II.17 O--CH(CH.sub.2 CH.sub.3).sub.2
______________________________________
In relation to the C.dbd.Y double bond, the compounds of the formula II can
be present in the E or the Z configuration (in relation to the carboxylic
acid function). Accordingly, they can be used in the mixture according to
the invention in each case either in the form of a pure E or Z isomers or
else in the form of an E/Z isomer mixture. The E/Z isomer mixture or the E
isomer is preferably used, the E isomer of compound II being especially
preferred.
The C.dbd.N double bonds of the oxime ether groups in the side chain of the
compounds II can exist in each case in the form of pure E or Z isomers or
in the form of E/Z isomer mixtures. The compounds II can be used in the
mixtures according to the invention as isomer mixtures or else as pure
isomers. With a view to their use, compounds II which are particularly
preferred are those where the terminal oxime ether group in the side chain
is in the cis configuration (OCH.sub.3 group in relation to ZR')
Due to the basic character, the compounds I and II are capable of forming
adducts or salts with inorganic or organic acids or with metal ions.
Examples of inorganic acids are hydrohalic acids such as hydrofluoric acid,
hydrochloric acid, hydrobromic acid and hydroiodic acid, sulfuric acid,
phosphoric acid and nitric acid.
Suitable organic acids are, for example, formic acid, carbonic acid and
alkanoic acids such as acetic acid, trifluoroacetic acid, trichloroacetic
acid and propionic acid, and also glycolic acid, thiocyanic acid, lactic
acid, succinic acid, citric acid, benzoic acid, cinnamic acid, oxalic
acid, alkylsulfonic acids (sulfonic acids having straight-chain or
branched alkyl radicals having from 1 to 20 carbon atoms), arylsulfonic
acids or -disulfonic acids (aromatic radicals such as phenyl and naphthyl
which have attached to them one or two sulfo groups), alkylphosphonic
acids (phosphonic acids having straight-chain or branched alkyl radicals
of from 1 to 20 carbon atoms), arylphosphonic acids or -diphosphonic acids
(aromatic radicals such as phenyl and naphthyl which have attached to them
one or two phosphoric acid radicals), it being possible for the alkyl or
aryl radicals to have attached to them further substituents, eg.
p-toluenesulfonic acid, salicylic acid, p-aminosalicylic acid,
2-phenoxybenzoic acid, 2-acetoxybenzoic acid etc.
Suitable metal ions are, in particular, the ions of the elements of the
second main group, in particular calcium and magnesium, and of the third
and fourth main group, in particular aluminum, tin and lead, and of the
first to eighth sub-group, in particular chromium, manganese, iron,
cobalt, nickel, copper, zinc and others. Especially preferred are the
metal ions of the elements of the sub-groups of the fourth period. The
metals can in this case be in the various valences which they can assume.
When preparing the mixtures, it is preferred to employ the pure active
ingredients I, II and III, with which further active ingredients against
harmful fungi or other pests such as insects, arachnids or nematodes, or
else herbicidal or growth-regulating active ingredients or fertilizers can
be admixed, if so desired.
The mixtures of the compounds I and/or II and III, or the simultaneous
joint or separate use of the compounds I and/or II and III, are
distinguished by an outstanding activity against a broad spectrum of
phytopathogenic fungi, in particular from the classes of the Ascomycetes,
Deuteromycetes, Phycomycetes and Basidiomycetes. Some of them act
systemically and can therefore be employed as foliar- and soil-acting
fungicides.
They are especially important for controlling a large number of fungi in a
variety of crop plants such as cotton, vegetable species (eg. cucumbers,
beans and curcubits), barley, grass, oats, coffee, maize, fruit species,
rice, rye, soybeans, grapevine, wheat, ornamentals, sugar cane, and a
variety of seeds.
They are particularly suitable for controlling the following
phytopathogenic fungi: Erysiphe graminis (powdery mildew) on cereals,
Erysiphe cichoracearum and Sphaerotheca fuliginea on curcubits,
Podosphaera leucotricha on apples, Puccinia species on cereals,
Rhizoctonia species on cotton, rice and lawn, Ustilago species on cereals
and sugar cane, Venturia inaequalis (scab) on apples, Helminthosporium
species on cereals, Septoria nodorum on wheat, Botrytis cinerea (gray
mold) on strawberries, vegetables, ornamentals and grapevines, Cercospora
arachidicola on peanuts, Pseudocercosporella herpotrichoides on wheat and
barley, Pyricularia oryzae on rice, Phytophthora infestans on potatoes and
tomatoes, Pseudoperonospora species on cucurbits and hops, Plasmopara
viticola on grapevines, Alternaria species on vegetables and fruit, and
Fusarium and Verticillium species.
Furthermore, they can be used in the protection of materials (eg. in the
protection of wood), for example against Paecilomyces variotii.
The compounds I and/or II and III can be applied simultaneously together or
separately or in succession, the sequence, in the case of separate
application, generally not having any effect on the result of the control
measures.
The compounds I and/or II and III are normally used in a weight ratio of
from 200:1 to 0.1:1, preferably 100:1 to 1:1, in particular 50:1 to 5:1
(III:I and/or II).
The application rates of the mixtures according to the invention are, in
the case of the compounds I and/or II, in general from 0.005 to 0.5 kg/ha,
preferably 0.01 to 0.5 kg/ha, in particular 0.01 to 0.3 kg/ha, depending
on the nature of the desired effect.
Correspondingly, in the case of the compound III, the application rates are
normally from 0.1 to 10 kg/ha, preferably 0.5 to 5 kg/ha, in particular 1
to 4 kg/ha.
For seed treatment, the application rates of the mixture are generally from
0.001 to 100 g/kg seed, preferably 0.01 to 50 g/kg, in particular 0.01 to
10 g/kg.
If phytopathogenic harmful fungi are to be controlled, the separate or
joint application of the compounds I and/or II and III or of the mixtures
of the compounds I and/or II and III is effected by spraying or dusting
the seeds, the plants or the soils before or after sowing of the plants,
or before or after plant emergence.
The fungicidal synergistic mixtures according to the invention, or the
compounds I and/or II and III, can be formulated for example in the form
of ready-to-spray solutions, powders and suspensions or in the form of
highly concentrated aqueous, oily or other suspensions, dispersions,
emulsions, oil dispersions, pastes, dusts, materials for spreading or
granules, and applied by spraying, atomizing, dusting, spreading or
pouring. The use form depends on the intended purpose; in any case, it
should guarantee as fine and uniform as possible a distribution of the
mixture according to the invention.
The formulations are prepared in a manner known per se, eg. by adding
solvents and/or carriers. It is usual to admix inert additives, such as
emulsifiers or dispersants, with the formulations.
Suitable surfactants are the alkali metal salts, alkaline earth metal salts
and ammonium salts of aromatic sulfonic acids, eg. ligno-, phenol-,
naphthalene- and dibutylnaphthalenesulfonic acid, and of fatty acids, of
alkyl- and alkylarylsulfonates, of alkyl, lauryl ether and fatty alcohol
sulfates, and salts of sulfated hexa-, hepta- and octadecanols or fatty
alcohol glycol ethers, condensates of sulfonated naphthalene and its
derivatives with formaldehyde, condensates of naphthalene, or of the
naphthalenesulfonic acids, with phenol and formaldehyde, polyoxyethylene
octylphenyl ether, ethoxylated isooctyl-, octyl- or nonylphenol,
alkylphenyl polyglycol ethers or tributylphenyl polyglycol ether,
alkylaryl polyether alcohols, isotridecyl alcohol, fatty alcohol/ethylene
oxide condensates, ethoxylated castor oil, polyoxyethylene or
polyoxypropylene alkyl ethers, lauryl alcohol polyglycol ether acetate,
sorbitol esters, lignin-sulfite waste liquors or methylcellulose.
Powders, materials for spreading and dusts can be prepared by mixing or
jointly grinding the compounds I and/or II and III or the mixture of the
compounds I and/or II and III with a solid carrier.
Granules (eg. coated granules, impregnated granules or homogeneous
granules) are normally prepared by binding the active ingredient, or
active ingredients, to a solid carrier.
Fillers or solid carriers are, for example, mineral earths such as silica
gel, silicas, silicates, talc, kaolin, limestone, lime, chalk, bole,
loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium
sulfate, magnesium oxide, ground synthetic materials, and fertilizers such
as ammonium sulfate, ammonium phosphate, ammonium nitrate, ureas, and
products of vegetable origin such as cereal meal, tree bark meal, wood
meal and nutshell meal, cellulose powders or other solid carriers.
The formulations generally comprise from 0.1 to 95% by weight, preferably
0.5 to 90% by weight, of one of the compounds I and/or II and III, or of
the mixture of the compounds I and/or II and III. The active ingredients
are employed in a purity of from 90% to 100%, preferably 95% to 100%
(according to NMR spectrum or HPLC.
The compounds I and/or II or III, or the mixtures, or the corresponding
formulations, are applied by treating the harmful fungi or the plants,
seeds, soils, areas, materials or spaces to be kept free from them with a
fungicidally active amount of the mixture, or of the compounds I and/or II
and III in the case of separate application. Application can be effected
before or after infection by the harmful fungi.
The fungicidal activity of the compounds and of the mixtures is
demonstrated by the following experiments:
The active ingredients, separately or together, were formulated as a 10%
emulsion in a mixture of 70% by weight of cyclohexanone, 20% by weight of
Nekanil.RTM. LN (Lutensol.RTM. AP6, wetting agent having emulsifying and
dispersing action based on ethoxylated alkylphenols) and 10% by weight of
Emulphor.RTM. EL (Emulan.RTM. EL, emulsifier based on ethoxylated fatty
alcohols) and diluted with water to give the desired concentration.
Evaluation is carried out by determining the infected leaf areas in
percent. These percentages are converted into efficacies. The expected
efficacies of the mixtures of the active ingredients are determined using
Colby's formula [R. S. Colby, Weeds 15, 20-22 (1967)] and compared with
the observed efficacies.
Colby's formula:
E=x+y-x.multidot.y/100
E expected efficacy, expressed in % of the untreated control, when using
the mixture of the active ingredients A and B at concentrations of a and b
x efficacy, expressed in % of the untreated control, when using active
ingredient A at a concentration of a
y efficacy, expressed in % of the untreated control, when using active
ingredient B at a concentration of b
The efficacy (W) is calculated as follows using Abbot's formula:
W=(1-.alpha.).multidot.100/.beta.
.alpha. is the fungal infection of the treated plants in % and
.beta. is the fungal infection of the untreated (control) plants in %
An efficacy of 0 means that the infection level of the treated plants
corresponds to that of the untreated control plants; an efficacy of 100
means that the treated plants are not infected.
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